Quote Originally Posted by merle&louise View Post
There has been a lot said about draining the oil when the bus is going to sit up for a long while.

What actually happens inside the engine if the oil stays in the oil pan for say 6 months or so?
I'm not sure what happens to the oil. The Series 60 manual does state however that if you're going to not operate the engine for more than 30 days to:

"Fill the crankcase to the proper level with Tectyl® 930A preservative lubricating oil or an equivalent 30–weight preservative lubricating oil
meeting Mil-L-21260C, Grade 2 Specification."